Guide

Frequent Questions

Short answers to questions that come up often.

General

Why Overplane?

Running overplane converts a directory of specs into functional, verified software.

Some reasons for using overplane as the tool of choice for this specific task are:

• Verification first: Every build raises each spec to a formal intermediate representation and checks it with the Z3 SMT solver (per spec and merged across specs) before any code is generated.
• Safety: Every agent run happens in an ephemeral local container (Docker or Podman) with the project mounted read-only; generated files are reconciled back only after a successful run.
• Multi-Agent: One vendor-neutral abstraction over Claude Code, Codex, and OpenCode. Bring your own API keys and pick the agent per project or per run.
• Caching: Content-hashed container images and content-addressable agent outputs make rebuilds incremental down to an individual spec, avoiding token waste.
• Cost reporting: Token usage and dollar cost are normalized across agent backends and reported per step and per build.

Why use this over Spec Kit?

GitHub Spec Kit is also spec-driven and multi-agent, but it is a set of slash-command prompts that run inside your existing coding agent, directly on your host. Overplane is a standalone build system. In practice that means:

• Isolation: Spec Kit agents run with full access to your machine; Overplane runs every agent in a sandboxed container.
• Verification: Spec Kit's quality gates (/speckit.clarify, /speckit.analyze, /speckit.checklist) are LLM-driven consistency reviews; Overplane additionally runs formal Z3 consistency checks on every spec.
• Caching: Spec Kit re-prompts from scratch; Overplane caches agent results so unchanged specs cost nothing to rebuild.
• Cost: Spec Kit has no built-in cost tracking; Overplane reports normalized token and dollar cost for every run.

See the full capability comparison (including AWS Kiro) on the homepage.